Some household appliances, for example, the electric iron, steam cleaner, steam vacuum, hair curling machine and microwave oven etc, usually contain a device relative to forming steam. Taking the electric iron for instance, steam given out from soleplate causes the ironed cloth to be humidified uniformly. The process is as below: Controlled by the valve, water is dropped into the forming steam chamber which is formed on the top of soleplate. When heating soleplate, water collides with the bottom of heated forming steam chamber, and is vaporized immediately, then steam bursts from the holes positioned on the bottom of soleplate. The other facility of forming steam used for the present household appliance is similar to that.
The method mentioned above has a drawback that water cannot be vaporized immediately, water droplets which are not vaporized are guided by formed steam, then burst with formed steam from the holes, so that the steam mixes with a lot of water droplets. It can not reach anticipated efficiency.